A Feast for Crows
Garrett, a child hostage serving at the court in King's Landing after House Paege submitted to the crown following the Red Wedding, is named a squire to Ser Jaime Lannister. He accompanies Ser Jaime on the ride north to end the siege of Riverrun.
When Ser Daven Lannister and Jaime discuss the lynching of Lannister foragers, Daven suggests that some riverlords might be responsible as they still support the northern cause, even though they have formally submitted to the Iron Throne. Jaime think to himself that he would hate to execute Garrett, as he has grown fond of the boy. Ser Jaime then suggests that Beric Dondarrion is a more likely suspect.